In a great section of Col Marshall and Tony Payne's The Vine Project they say "one of the culture changes that many churches need is a revolution in their level of gospel ambition. Putting it baldly, we need to think big." They make a biblical case for gospel ministry 'ambition'. Yes!

But then they have a few really searching paragraphs that analyse the dangers for finite and sinful people in gospel ministry ambition:

There are of course dangers in thinking big. There’s the credibility danger of creating disillusionment in the congregation by setting some pie-in-the-sky goal that we’ll never achieve. And if we talk big but act small (like not providing for more people on Sunday, or not equipping ministry leaders), then no-one will believe us.

There are also spiritual dangers in having ambitious plans:

you might begin to lust for the glory and reputation that accrues to the minister of a large and growing church

you might be tempted to build a feel-good, people-pleasing ministry in order to attract the crowds

you might start to treat people like objects, and lose the compassionate inefficiency that leaves the 99 in order to seek after the one

you might start exaggerating or fudging the facts to protect your credibility (i.e. by making out that goals are being achieved when they’re not)

you might fall into the unprincipled pragmatism that follows any ministry method that ‘gets results’.

(Page 300, emphasis mine)

'Compassionate inefficiency' is a lovely turn of phrase, isn't it? But the whole thing is spot on. It's helpful to take the time to list these various temptations and corruptions like this. Rather than careless and general warnings, this kind of specificity is really shocking in a good way.